Method of and apparatus for straightening steel strapping



Dec. 20, 1938. c. M. M CI -IESNEY METHOD OF ANDAPPARATUS FOR STRAIGHTENING STEEL STRAPPING Filed June 25, 1936 2 Sheets-Sheet l PING 2 Sheets-Sheet 2 20, 1938. c. M. M ficHEsNEY, i

. METHOD OF AND APPARATUS FOR STRAIGHTENING STEEL STRAP Filed June as, 1936 Patented Dec. 20, 1938 I PATENT OFFICE mnon or AND maaa'rusron smsran'mume swam. smarrma Chester M. MacChe'sney, Chicago, 111., amino:-

ioration of Illinois to Acme Steel Company, Chicago, 11].,

Application June as, me, Serial mi. $1,140

"9Claims.

This invention relates to improvements in methods of and apparatus for straightening strip metal and the like and its purpose is to provide improved means by which elongated metal strips may be straightened and flattened. Strip steel, such as that employed in binding boxes, bales and the like, and for various other purposes, is rolled in long continuous strips and it is frequently found that when it comes out of the mill it has a lateral curvature or a multiplicity of lateral curvatures in its own plane, called "camber", which interferes with the winding of the strip in a coil and prevents its use for most purposes. It has heretofore been necessary to scrap-a great l5 deal of this imperfect. strip metal and quantities of this material are frequently returned-by customers because of defects in this respect. The

present invention involves the discovery that this lateral curvature instrip steel and the like may be removed by an improved process of bending and stretching the material while it is under tension with the result that the metal on the side of the strip which 'is shorter is stretched and elongated so that the opposite edges of the strip are restored to their desired parallel rela= tionship. This improved process is preferably carried on by moving the elongated metal strip .which are arranged to cause the strip to follow 7 a staggered or zigzag path and which are preferably provided with means for preventing the lateral shifting of the metal strip longitudinally of the rolls sothat, as the strip is bent back and forth between the rolls, the shorter portions thereof are elongated and the metal strip emerges from the rolls in a flat condition with parallel edges so that it may be wound in'a coil and used .for all'purposes for which such strip metal is ordinarily employed. The apparatus of the presmetal strip is bent sharply back and forth as it passes between these rolls under tension, which is created preferably by driving oneseries of friction rolls slightly faster than the other series of friction rolls. or employing friction rolls in oneseries which differ slightly in diameter from those of the other. The elongated metal strip which is to be straightened is initiallysvound upon a reel and is progressively unwound therefrom as it is drawn through the friction rolls' and s5 straightening rolls after which the straightened while under tension through aplurality of rolls' strip is rewound upon another reel in readiness for distribution to the customer. Other objects of the invention relate to various features of construction and arrangement and to details of the method of straightening which will appear 5 more fully hereinafter.

The nature of the-invention will be understood from the following specification taken with the in practicing the invention. In the drawings. Fig.- 1 shows a somewhat diagrammatic side elevation of the improved apparatus which is employed in the straightening process of the 18 present invention;

. v Fig. 2 shows an enlarged top plan view ,of a

shortlength of strip steel or the like whichhas a lateral curvature of the type which is adapted to be corrected by the use-of the present inven- 20 tion; r

Fig. 3 shows an enlarged vertical section through the straightening rolls which are embodied in the apparatus illustrated in Fig. 1 andshowing portions of adjacent friction rolls; 25

Fig. 4 shbws a top plan view of one form of apparatus embodying the features illustrated in Fig. 5 shows a side elevation of the apparatus illustrated in Fig. 4;

Fig. 6 shows an enlarged detail section on the line 86 of Fig. 4; and

Fig. 7 is a sectional view similar to that of Fig. 6- showing a modified form of straightening roll adapted for use in straightening metal strips of at considerable width.

' In Fig. 2 of the drawings, there is illustrated a portion of an elongated section of strip steel i 0 or the like which has a lateral curvature or cam first in one lateral direction and then in the othe 40 as shownpby the relative positions of the edges iii and iii of the strip with reference to the. lines III which represent the edges of the strip if it were straightwith its lateral edges parallel to each other. In practice, these lateral curva- 46 tures, in the plane of the strip, may succeed each other in quick succession or they may appear only at intervals with long stretches of straight strapping between them, or they may be continuous in' the same direction from end to end of the coil. 50v

In either event, this lateralcurvature causes the metal strip to wind in irregular fashion upon a reel and it has been found that if elongated strip metal'of this character he moved while under longitudinal tension in a zigzag path through a It series of idler rolls, the metal in passing through these rolls will stretch along those side portions thereof which are shorter, provided the strip be restrained against-lateral movement between the rolls, and, by this process of stretching, the successive shorter side portions of the strip are elongated until they are of the same length as thegation at the point ll! to bring about a parallel relationship of the opposite edges and a graduated stretching of intermediate parts so that these-intermediate parts are in flat condition will]? the strip emerges from the straightening ro .The apparatus for practicing the method of the present invention is illustrated diagrammatically in Fig. l, where the elongated metal strip Ill of steel or the like is shown as beingwithdrawn from a reel I I and moved in the direction. of the arrow i2 by means of a series of driven friction rolls l3 which are comparatively large in diameter and which are arranged in zigzag fashion so that the strip is compelled to follow an irregular path in passing through this series of rolls, thereby obtaining a large area of contact between the strip and the surface of each roll.

The strip in then passes in zig-zag fashion through a series of parallel straightening rolls it which are comparatively small in diameter and g which operate as idler rolls arranged with their lateral movement as it passes between these rolls.

axes in one-plane', so that the metal strip is bent back and forth between these rolls as it passes through them, being preferably restrained against The strip "I then passes through or around a series of friction rolls I! which are power driven and which pull the strip under tension through the straightening rolls ll; Upon emerging from the rolls it, the strip ii-is wound upon a reel l6,

which maintains the strip under suflicient tension-in the process of winding to hold it in contact with the friction rolls IS. The friction rolls 5 5 are preferably slightly larger in diameter than the rolls is if the rolls of the two series are driven than the peripheral speeds of the'rolls it, whichcreates a substantial tension in a longitudinal at the same angular speed, or the rolls I! are driven slightly faster than the rolls It, so that the peripheral speeds of the rolls I5 are greater direction in the strip III as it passes through the strip passes through the rolls all, the tension" intervening idler rolls I. Some slippage is provided in the driving mechanism of the friction rolls so that the tension created in the strip i isnot sufficient to elongate the strip generally throughout its width and the result is that as the therein is sufficient to stretch the shorter edges of the strip until these shorter edges are of the same length asthe opposite longer edge portions.

A brake is appliedto the supply reel I i to prevent the metal strip frombeing withdrawn therefrom too rapidly, thereby maintaining it in close contact withthe rolls l3, and the driving mechanism which is connected to the winding reel I6 is providedwitha-friction clutch which'is adapted tci slip when remrired so that if the reel l I be driven.

at a greater speed than the friction rolls is the preferred practice, the friction clutch may slip and at the same time maintain the strip sumcientiy taut between the rolls i and the reel It to bring about a tight winding of the strip in the 'coil and at the same time keep the strip in close contact with the surfaces of the rolls l5.

The apparatus, as illustrated more in detail in Figs. .3 to "I, inclusive, comprises a frame 20 having mounted thereon bearings 2| in which is journaled a shaft 22. This shaft is provided with a brake drum 23 engaged by a friction brake strap Hand the projecting end of the shaft has secured thereon the reel ii on which the metal strip to be straightened is wound. This drum i i has a disk 25 at one side thereof and its periphery is slotted, as shown at H for engagement by the inner end of. the'strip. As the strip is unwound from this drum, the brake 23-24 prevents the drum from unwinding too freely and the brake strap is capable of adjustment for the purpose of regulating the resistance which isinterposed to the unwinding of the strip. The friction drums it, about which the strip it passes in advance of the straightening rolls M, are carried by a frame 26 which is. mounted on the'fioor or base 21 by which the frame2ii is carried. This frame 26 comprises longitudinal frame members 26 carrying bearings 21 in which are journaled a plurality of transverse shafts 28 on the'projecting ends of which the friction rolls I 3 are secured. These rolls are of suillcient width tp accommodate any widthofstrip metal to be straightened and they are provided at their edges with flanges l3a to retain the metal strip in position thereon. The

shafts 28 are so positioned that the rolls i3 have an irregular zigzag arrangement so that the metal strip ll follows a corresponding sinuous course in passing through these rolls and is compelled to contact with a considerable portion of the surface s of each roll. The, shafts 28 are driven from a parallel shaft 29 which is journaled in bearings secured to the under sides of the frame members 26 and this shaft carries a pinion 30 which meshes with two gears 3| fixed on two of the i shafts 28. These two gears mesh with other gears 3! fixed on the other shafts 28, as shown in Fig. 5, so that when the shaft 29 is driven as hereinafter described, all of the shafts 28 are driven in the proper directions to advance the strip i0 through these rolls when the apparatus is in operation. The end ofv the frame" carries a transverse'member 32 which is provided with a slot 22' in its upper flange for engagement by a pair of pins 33 which extend vertically and have rollers-34 mountedthereon. These rollers 34 are positioned on opposite sides of the strip III and are adapted to maintain the strip in proper alignrnent with the straightening rolls I 4 as the strip moves through the apparatus. The pins 33 are adapted to be clamped in the desired adjusted position to'accommodate strips of various widths. The rolls I! are fixed on the ends of a plurality of shafts 88 which are journaled in bearings 39 carried by the longitudinal frame members m of another frame 40 which is carried by the base 27. The rolls l5. are provided with flanges IE to retain the strip i0 inposition thereon and they are arranged in zigzag fashion like the rolls is so that the strip l0 coacts with a considerable portion of the periphery of each roll. The shafts 38 are driven by a shaft 4| which has a pinion 42 secured thereon and arranged to mesh with two of the gears 43 which are secured on two .of the shafts ll. Other gears are secured upon the 1 and another similarball bearing unit. 4! engages the flange i4 carried by the other end of the roller and is located within the inner end of amazes each other in such a manner um the shafts a are all driven in the proper directions when the shaft 4i is actuated as hereinafter described.

The straightening. rolls l4 are carried by an intermediate frame 44 which is in the form of a heavy angle bar having its ends resting upon and secured to the frames 28 and 40, as shown in Fig. 5. The frame 44 has an upwardly extending flange 44', shown in Fig. 6, in which are secured the inner reduced ends of a series of stationary spindles or axles 45' upon which the straightening rolls l4 revolve. These spindles have enlarged collars 45 which coactwith the outer faces of the frame members' 44 and their inner threaded extremities are engaged by nuts 48 by which the spindles are clamped securely in position on the frame. Each roll I4 is in the form of a cylindricalJsleeve adapted to revolve about the body portion of one of the spindles 45 and it has secured to the ends thereof a pair of annular flanges or collars I 4' which are adapted to engage the lateral edges of the strip in to hold the strip against lateral movement as it passes through these straightening rolls. A ball bearing unit 41 is mounted on each spindle 4! between the roller i4 and the adjacent collar is provided on its outer side with recesses 49' which may be engaged by a wrench for adjusting the member to the proper position to secure the I ball bearing units 41 and 48 and the intermediate roller i4 against endwise movement on the spindie.

I justed position by a locking member 52 which is internally threaded to engage the member 80 and which is provided externally with recesses 52' for engagement by a wrench. The outer ends of the spindles 45'are reduced in diameter as shown at 45 and-these parts are arranged to flt aper-.

rod which extends between the parts 44' and 53. This roller 54 located above the metal stripill imparts a reverse bend to the metal so that it has no tendency to. remain coiled in one direction after passing through the rolls I! or after .being removed from the reel It. The roll II which is located. nearest .to the. friction rolls II is providedwith end flanges or collars l4 which are considerably larger in diameter than the flanges I4 carried by the other rolls l4 so that the strip II is properly, guided. in'its passage to the roll i4 from the rolls IS. The flanges l4 at each end of each roll I 4 should be in absolute alignment, as. nearly as practicable, with the flanges at the same end of each of the other rolls l4.

The apparatus described above is driven by an electric motor I which has a shaft '1' provided with a relatively fixed pulley 82. A belt '4 passes over this pulley and over another pulley 4 which is secured upon the projecting extension of the.

The adjusting member 49 is secured in adshaft u previously described. The adjacent end of this shaft is journaled in a bearing block 68 to the frame 40. A belt 6'! passes around the pulley l8 and around another pulley 08 which is secured upon the shaft 29 referred to above. In this way, the power derived from the motor ll is utilized to drive both of the shafts 29 and 4i which operate the friction rolls l3 and I 5, respectively. Since the rolls iii are slightly larger in diameter than the rolls ii, for example, a few thousandths of an inch, the rolls I! tend to pull and a pulley It is secured on the shaft adjacent the strip "I through the straightening rolls l4 at a greater speed than that with which the strip is supplied to the rolls I 4 by the rolls I 3, and in 1 order to retain the desired degree of tension in the strip is, while it is in engagement with the rolls i4, by this method, without unduly stretching or breaking the strip, some slippage of the belt 61 on the pulleys 46 and 68 is permitted during the operation of the machine. In order to regulate this slippage for the purpose of maintaining the desired tension in the strip, means are provided for adjusting the tension of the belt 61. These means include a roller 10 which revolves on a pivot pin Ii carried by the free ends of a pair of arms 12 having their lower ends pivoted on a shaft 13 carried by av bracket 14 projecting from the frame 2B. The shaft 13 has secured thereon ado'wnwardly extending arm 15 which is apertured'at its lower end for engagement by a stud 18 having its inner end threaded into a hole in the adjacent frame member. A nut ll threaded on the stud I6 is adapted to engage the outer face of the arm 15 to limit the outward movement of this arm and 'the corresponding upward movement of the roll .10. As a further means of regulating the tension of the belt 61, a bell crank lever 18 is' pivoted at I! .on a bracket Ill carried by a frame 40 and one arm of this bell crank lever gis bifurcated to receive a bell crank lever 18 is apertured for engagement by a stud 82 which is threaded into the adjacent vertical member of the frame 40. A nut 83 threadedly engages the stud 82 to limit the outward swing of the upper arm of the lever 18 and thereby limit the downward movement of the roller 8i which coacts with the belt. By regulating the extreme positions of the rollers I0 and Bi, the slippage of the belt '1 may be regulated as desired.

With the apparatus described above',metal strips III of varying widths may be straightened by reason of the fact thatany particular set of rolls i4 may be interchanged with other rolls of difl'erent lengths by. removing the bar 53 and the parts 49, 50, 5i and 52 and replacing the rolls l4 .by other rolls of different length. When straightening a metal strip l I which is comparatively narrow and heavy, it is desirable to use rolls i4 having aligning flanges i4- which are spaced apart a distance substantially equal to the width of the strip,'so

- other, instead-of shifting endwise of the rolls i4, v which would be the natural tendency of the strip if it were not restrained. The use of rolls l4 having flanges l4 which are spaced'precisely in this manner is recommended for the straightening of metal strapping or other metal strips of any gauge i where it is used to define a normally flat metal vention is capable of being used satisfactorily to straighten strip metal of considerable width without positively restraining the strip against lateral movement by flanges located'at the ends of the straightening rolls, and' there is illustrated in Fig. 'I a modified form of straightening roll which may be employed when operating upon metal strips of considerable width. .In this view, the member I; corresponds to the upstanding portion "a of the frame member previously described and it has' mounted therein a series of spindles 85 which correspond in form and method of mounting to the spindles 45 previously described, being secured in place within the frame member 44 by nuts 86. The rolls which are mounted to revolve on the spindles 85 are comparatively long to accommodate astrip Iii of substantial width and although the rolls I4 afe provided at their ends with flanges W, these flanges are not so spaced as to engage the edges of the strip i and metal strips having a considerable range of width may be rolled with one series of rollers M The flanges it" carried by the rolls W are engaged at their ends by ball bearing units 81 and a collar 88 is secured upon the threaded portion 85 at the outer end of each spindle to hold the adjacent ball bearing unit in position. The threaded portions 85 of these spindles are engaged by nuts 90 and the-outer reduced ends 85 of these spindles engage a bar, 93 which corresponds to the bar 58 described above.

Although one form of the improved apparatus has been shown and described, with a modifica-' tion of the construction and mounting of the straightening rolls, it will be understood that the improved apparatus and the method of straightening maybe modified without departing from the scope of the appended claims. In the claims, the term metal strip" is to be understood as having the meaning given to it in the steel industry,

strip produced by a rolling process and where it is distinguished from wire, whether the wire be of round or other cross section.

I claim:

l. The method of removing lateral curvature from an elongated metal strip which consists in running the strip endwise along a zigzag path, restraining the strip against lateral movement as it travels along said path and thereby maintaining itsedges substantially in parallel frames, and

the strip is adapted to travel in a sinuous path,

meansv for maintaining the edges of said strip substantially in parallel planes as it travels through said rolls, and means for moving the strip through said rolls and maintaining it under tension to stretch the shorter sideportions thereof.

3. The combination in apparatus for'removingllateral curvature from an elongated "metal strip, of a set of straightening rolls through whichthe strip is adapted to travel in a sinuous path, means for maintaining the lateral edges of said strip substantially in parallel planes as'it travels alongsaid path, a power driven winding reel for winding said strip after it has passed through said straightening rolls, a supply reel from which the strip to be straightened is unhas been found that the method of the present inwound, two series of friction rolls, each series of friction rolls being engaged by said strip between one of said reels and said straightening rolls,

and power means for driving each series of friction rolls, the friction rolls in advance of said straightening rolls being adapted to move said strip at a lesser speed than the friction rolls which follow said straightening rolls, whereby suiiicient tension is maintained in said strip to stretch the shorter side partions thereof.

4. The combination in apparatus for removing lateral curvature from an elongated metal strip.

of a set of straightening rolls through which thestrip is adapted to travel in a sinuous path, a power driven winding reel for winding said strip after it has passed through said straightening rolls, a supply reel from which the strip to be straightened is unwound, two series ofiriction rolls, each series of friction rolls being engaged by said strip between one of said reels and said straightening rolls, the friction rolls in advance of said straightening. rolls being adapted to move said strip at a lesser speed than the friction rolls which follow said straightening rolls, and

means for interconnecting the driving means of a said two series of friction rolls to permit a predetermined slippage in the driving connection of one series of friction rolls whereby said strip is maintained at a predetermined tension as it passes through said straightening rolls.

straightened is unwound. two series of friction rolls, each series of friction rolls being engaged by said strip betweenone of said reels and said straightening rolls, the'friction rolls of one series tending to move said strip at a greater speed than the rolls of the other series, a pair of shafts each adapted to drive one series of friction rolls, power means for operating one of said shafts, a pair of pulleys each mounted on a separate one of said shafts, a belt extending around said pulleys, and

adjustable means engaging said belt for regulating the slippage of said pulleys.

6. The combination in apparatus for remoying lateral curvature from an elongated metal strip, of a set of straightening rolls through which the strip is adapted to travel in a sinuous path, a power driven winding reel for winding said strip after it has passed through said" straightening rolls,a supply reel from which the strip to be straightened is unwound by said firstnamed reel. two series of friction rolls, each series being engaged by, said strip between one of said reels and said straightening r is, said strip being adapted to .follow azigzag pa h through each of said series'of friction rolls, one series of friction rolls being of such diameter that they tendto move said strip at a greaterspeedthan the rolls of the other series when driven at the same angular speed, a pair of shafts each adapted to drive one series of friction r0118. power means for operating one of said shafts, a pair of pulleys each mounted on a separate one -of'said shafts, a belt extending around said pulleys, and adjustable 7. The combination in apparatus for straigh ening an elongated; metal strip, of a series of straightening rolls through which the strip is 18 said cap member and adapted to retain the ad-- adapted to travel along a sinuous path in engagement with successive rolls, a frame, a spinpermitting each roll to be replaced by other rolls of diflierent width, said fastening means for. each roll comprising an external threaded cap member mounted on said spindle, a sleeve threaded on jacent roll against endwise movement, and a nut threadedly engaging said cap member for securing said sleeve in adjusted position. v

8. The method of removing camber from an elongated metal strip which comprises the steps of running the strip endwise in a sinuous path with the shorter edges only of the strip in contact with means determining the form of said path, restraining said strip against lateral movement during its travel, and maintaining the strip under sumcient tension to efl'ect a. progressive I stretching oi the metal between its shorter and longer edges whereby the opposite edge portions of the strip assume the same length and becom parallel with each other.

9. The combination in apparatus for removing lateral curvature from an elongated metal strip, of a set of straightening rolls through which the strip is adapted to travel in a sinuous path, means for maintaining the edges of said strip substantially in parallel planes as it travels along said'path, a power driven winding reel for moving said strip through said straightening rolls, a supply reel from which the strip to be straightened is unwound, a series of friction rolls engaged by said strip between each of said reels and said straightening rolls, and means for driving said friction rolls in such a manner that suiilcient tension is maintained in said strip to stretch the shorter side portions thereof.

CHESTER M. MACCHESNEY. 

